en=float(input())
ma=float(input())
pc=float(input())
if en>90 or ma>90 or pc>90:
   en_score=4.0
   ma_score=4.0
   pc_score=4.0
else:
    en_score=4.0*en/90
    ma_score=4.0*ma/90
    pc_score=4.0*pc/90

GPA=(en_score*3+ma_score*4+pc_score*5)/(3+4+5)
print(f"GPA:{GPA:.1f}")